Skate-grinding machine



March 18 1924.

v. A. BOKER SKATE GRINDING MACHINE Filed April 5, 1.922 s Sheets-Sheet 1March 18, 1924. 1,487,142

v. A. BOKER SKATE GRINDING MACHINE Fiied April 5, 1922 5 Sheets-Sheet 2J5 M161 w megf,

March 18 1924. 1,487,142

v. A. BOKER SKATE GRINDING MACHINE Filed April 5, 1922 3 Sheets-Sheet 3ma/w J9 kwflii-orneys Patented Mar. 18, 1924.

VITUS A. BOKER, 0F MINNEAPOLIS,MINNESOTA.

SKATE-GRINDING MACHINE.

Application filed. April 5, 1922.

T 0 all whom it may concern Be it known that I, Vrros A. BOKER, acitizen of the United States, residing at Minneapolis, in the county ofHennepin and State of Minnesota, have invented certain new and usefulImprovements in Skate- Grinding Machines; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

My invention relates to skate grinding or sharpening machines and hasfor its object to improve the same in point of simplicity and highefficiency. Generally stated, the invention consists of the noveldevices and combinations of devices hereinafter described and defined inthe claims.

This improved skate grinding machine is adapted both for use infactories for the initial grinding or sharpening of the skates and foruse elsewhere for commercial regrinding or sharpening skates. Theimproved machine has various important novel features which make therapid and accurate grinding of the skates possible and which willhereinafter appear in connection with the description of a commercialmachine embodying my invention. This commercial machine, as illustratedand as preferably designed, w1ll slmultaneously grlnd two skates toexactly the same lines, but certain of the features of the inventionmight readily be incorporated in a more simple form of machine arrangedto grind but one skate at a time.

In the drawings, which illustrate the commercial machine, likecharacters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a plan view of the improved grinding machine showing twoshoeequipped skates clamped in position for grinding of the skaterunners;

Fig. 2 is a fragmentary detail in vertical section on the line 2-2 ofFig. 1;

Fig. 3 is a left side elevation of the machine andskates shown in Fig.1, some parts being broken away; and

Fig. 4. is a front elevation of the parts shown in Figs. 1 and 3, someparts being sectioned and some parts being broken away.

The running parts of the grinding machine are directly or indirectlymounted on a cast base 5 provided with laterally spaced pedestals 6 inwhich is journaled a wheel Serial No. 549,787.

shaft or spindle 7. This shaft 7 midway between the pedestals 6, isprovided'with a pulley 8 that serves to space apart two simi-' largrinding wheels 9. The pulley 8 will slide on and off from the shaft 7but may have a. key for positively causing the same to rotate therewith.One of the grinding wheels 9 isclamped against a flange 7 fixed on theshaft 7 and the other wheel is pressed by a washer 10 that is subject toa nut 11 that works with threaded engagement on said shaft 7. Thisprovides an arrangement in which the grinding wheels and the pulley maybe easily removed from and applied to the shaft 7, when said shaft islifted out of its bearings in the pedestals 6. To permit this latteroperation, the upper halves of the pedestal bearings are made removableand, as shown,'they are formed integral with cross arms 12' detachablysecured to said pedestals by machine screws 13.

At one'projecting end, the wheel shaft 7 is provided with a worm 14 thatmeshes with a worm gear 15 located within a housing rigidly secured toone of the pedestals 6 and, at its outer end, supporting along'transversely extended bearing sleeve 17. Said worm gear 15 issecured on a shaft 18 journaled in the bearing plates 16 and provided atone end with a worm 19 that meshes with a worm gear 20 carried by asleeve 21 journailed on a long'stud 22 secured to a lug 23 on theadjacent pedestal 6. At its extended end, the sleeve 21 carries a camhub having a peripheral cam groove 24 that performs a function presentlyto be noted.

Mounted to' slide horizontally through bearing sleeves 12 at the ends ofthe cross bars 12, is a pair of horizontally parallel plungers orendwise movable rods 25, which, at the right-hand side of the machine,are cross-connected by a tie-rod 26. This tierod, close to the plungers25, is engaged by the forked upper ends of arms 27 rigidly secured to arock shaft 28 mounted in the 7 bearing sleeve 17. The rock shaft 28 hasa depending arm 29'provided at'its lower end with an offset pin 30 thatworks inthe cam slot 24.

Rigidly secured tothe plungers 25, between the aligned bearing sleeves12 are shaft bearings that are formed with horizontally aligned bearingsleeves 31 and with vertical bearing sleeves 32. A cross shaft 33 isjournaled in the aligned bearing sleeves 31 and vertically movablep-lungers or supporting posts 34 are arranged to move vertically in thevertical sleeves 32. The shaft 33 is cut to form small pinions 35 thatmesh with rack teeth 36 cut in the vertically movable plungers or posts34, so that, under rotation of said shaft 33, the two plunger-s 34 willbe given simultaneous and equal vertical movements.

Laterally spaced parallel and horizontally extended guide rails or bars37 are rigidly secured to the reduced upper ends of the plungers 34. Anarrow guide channel, extending from front to rear of the machine, isformed between the upper portions of the guide rails 37. In this,preferred arrange ment, a segmental guide block 38 is rigidly securedfor vertical adjustments to and between the central portions of theguide rails 37, by means of nut-equipped bolts that work in verticalslots in said guide block. The curvature of this guide plate 38 shouldbesomewhat less than that of the grinding wheels '9, but its uppermostportion should be set tangential to a horizontal plane that is alsotangential to the tops of said grinding wheels.

At its front end, the shaft'33 is provided with a worm gear 40 that islocated within a housing 41 that is rigidly secured to the adjacentshaft bearing 31-32. This worm gear 40 is engaged by a worm 42, theshaft of which'is journaled in the housing 41 and is provided at oneprojecting end with an operating crank 43.

The skates A illustrated in the drawings are of the tubular type and areshown as secured to shoes B. The skate clamp for holding two such skateswith the shoes applied, with their runners parallel, is preferablydesigned as follows: The numeral 44 indicates the so-called carriage barthat is formed on both sides, near its ends, with short outstanding arms45that terminate in heads 46 formed with V-shaped channels to lit thetubes of the skates. The numeral 47 -indicates curved clamping jaws,which, as viewed in front elevation, Fig. 4, are approximately C-sh'apedand extend two hundred and seventy-five degrees, more or less, of acircle. At their inner ends, said clamping jaws 47 are pivoted at 43 toupstanding lugs 49 on the carriage bar 44. The outwardly and downwardlyextended free ends of said jaws 47 are pronged or bifurcated, as bestshown in Fig. 3, and the free ends of said prongs are formed with heads50 that have i-shaped grooves opposed to the V-shaped grooves of theheads 46 and cooperating therewith to clamp the tubes of the skates. Thesaid heads 46 and 50 are preferably, and as shown, provided withclamping screws 51 that are adapted to be set so that they will clampthe runners of the skates.

At the point where the clamping jaws 47 conver e, as viewed in Fig. 4,and down to the pivot 48, one of said jaws 47 is bifurcated so that itembraces the other jaw, and this bifurcated jaw is provided with bearingsleeves 59 in which is detachably journaled a clamp-actuating shaft 53.This shaft 53 is flattened at 54, from its inner end rearward, so thatsaid shaft may be freely inserted to position when its flat tenedportion 54 is turned into alignn'ient with a lug 55 on the otherclamping 'aw. At its extended end, the clamping shaft 53 has a handpiece 53*, by means of which it may be readily turned.

For co-operation with the carriage bar 44 and the guide rails 37 formoving the skates in the planes of the grinding wheels 9 and forproperly guiding the skate runners to said grinding wheels, 1 pro ido atemplate bar 56, the lower edge of which will have approximately theline or desired line of the edges f the skate runners to be sharpenedand, of course, there may be different templates for different skaterunners. The template 56 fits a channel formed in the under side of thecarriage bar 44 and is of the proper width to fit quite closely but tomove freely between the guide rails 3'7. As a means for securely butdetachably and adjustably holding the template 56 to the car-- riage bar44, said template is formed with a longitudinal groove that receives thenotched heads 57 of adjusting screw-threaded studs 58 mounted for freevertical movements in the ends of the carriage bar 44 and provided attheir threaded upper ends with adjusting nuts 59. Also, the carriage bar44 is provided with set screws 60 that work with threaded engagementthrough the top thereof and are adapted to press against the upper edgeof the template. By vertical adjustments of the studs 58, the templatemay be vertically adjusted in respect to the can riage bar, and bytightening the set screws 60, said template may be locked in any setadjustment and securely held against webbling or other movements inrespect to the carriage bar.

The use and operation of the machine in sharpening skates issubstantially as follows:

While the carriage bar 44 with its attached skate clamp is removed fromworlc ing position and the jaws of the clamp are opened up, the twoskates may be clamped. as shown in the drawings. The jaws of the clampmay be freely opened up when the clamping shaft 53 is pulled out of thesleeves 52 and when the clamping jaws 47 are thus released, they may befreely moved so as to embrace the skates and shoes and properly positionthe clamping heads 46 and 50 against the two skates. When the flatsurface 54 of the shaft 53 is turned into alignment with the edge of thelug 55, it

may be freely inserted into the sleeves 52 and then, when given about ahalf rotation, the uncut portion of said shaft will be forced againstthe lug 55, thereby clamping the heads 46 and 50 tightly against theskates, thus clamping the two skates with their runners parallel andwith the edges of the runners transversely aligned. By then placing therunners of the skates on-a fiat surface, the lower edge of the template,56 can be adjusted so that it will be approximately in transversealignment with the edges of the two runners. It is assumed that theuppermost portion of the guide segment or block 38 is in transversealignment with the uppermost portions of the two grinding wheels 9.

When the skates are to be ground, the lower edge of the template isinserted between the guide rails or bars 37 and, when the conditions areas above described, if the carriage bar 44 be moved horizontally backand forth with the template running in the channel between the rails 37and resting on the guide segment 38, the lower edges of the runners willbe moved over the upper surface of the grinding wheels and will beground to a form corresponding to the lower edge of the template. Thisgrinding of the runners to the form of the template need not be made byone out or movement, but may be produced by several to and fromovements. In fact, it is of the utmost importance that the skaterunners be allowed to slide freely and lightly over the grin-dingwheels, so as to sharpen the runners without overheating the same, forit has been found that where the runners are positively held and theweight of the grinding wheels, for example, is exerted in the grindingaction, there is sure to be an overheating such as will take the temperout of the skate runners and materially damage the same.

. It may be here noted that while it is true that if the carriage bar 44be held absolutely horizontal while moving to and fro, the skate runnerswill be ground to the outline of the template; it is, nevertheless, afact that by rocking the template on the guide block or segment 38 asthe ends of the template approach said block, the run- 7 ners may begiven a somewhat greater ourvature than the template at the front andrear ends.

Where it is not deemed necessary or 'de sirable to change the curvatureof the skate runners or to give an exact form thereto, the guide segmentor block 38 may be removed, in which case the grinding of the skatesmust be regulated by the operator, although, even in this event, theguide rails 3'? direct the skate runners for true movements in theplanes of the grinding wheels.

It is evident that if the skate runners should be moved back and forthfor a conto slowly drift back and forth. over the grinding faces of thewheels 9 throughout the grinding action. i

By rotation of the worm 42, the vertically movable plungers or posts 34and the guide rails 37 and guide segment 38 carried thereby may 'bevertically adjusted and.

set in any desired or proper operative position. The guide rails 37,throughout the operation of the machine, keep up a slow lateral shiftingmovement, first in one direction and then in the other, so that, 019-crating 0n the template 56, they cause the carriage bar 44, the clampand the skates to partake of the above noted lateral to and fromovements.

The numeral 61 indicates a power-driven driving belt which, as shown inFig. 3, passes through an opening in the base 5 and runs over the pulley8. This belt 61 is considerably more narrow than the distance betweenthe grinding wheels.

What I claim is:

1. In a skate grinding machine, the combination with a grinding wheel,of a guideway extended parallel to the plane of said grinding wheel, anda skate holder movable on said guideway above said grinding wheel andoperating to direct the skate blade against the upper portion of saidgrinding wheel, said skate holder being held against lateral shiftingmovement and angular movement in a horizontal plane but free forvertical movement and displacement and adapted to be moved endwise byhand operations.

2. The combination with an upright grinding wheel working in a vertical.plane, of an approximately horizontal guideway extended in a planeparallel to the plane of said grinding wheel, a skate holder normallyfree for vertical displacement from said guideway but having a templatearranged to run in said guideway and adapted to direct the skate runneragainst the grin-ding wheel under the action of gravity and handoperations applied to said skate holder, said skate holder being heldagainst lateral shifting movement and angularmovement in a horizontalplane.

3. The structure defined in claim 2 in further combination with a guideblock associated with said guideway and set with i s upper portiontransversely; aligned with the upper portion of said grinding wheel.

4. The structure defined in claim 2 in which said template is secured toair holder vith freedom tor adpistniel c i Y the plane parallel to theplane oi? the skate runner.

5. The

combina n with an uprightgrinding wheel working in a vertical plane ofan approximately horizontal guidewa Y ing wheel unde han d operati on sa; L er and a said gui len tron transversely aligned with block beingre-rt! to the guideway.

6 The structure defined in claim 2 in further combination 'vith meansfor vertically ad usting said guzdeway.

7. The structure delii'ied in claim :2 in iui thor combination withanton'iatically moving said guide-Nay later l v so as to shift the skaterunner on the face of the grinding wheel during the skate grindingaction.

8. The combination with two laterally spaced grinding wheels and meansfor rotating the same, of a guideway extended in aplane that is parallelto but between said grinding wheels, a skate holder having clamps forholding two skates with their runners in parallel relation said skateholder having a template freely movable in said uideway and arranged todirect the two skate runners against the two grinding wheels under theaction of gravity and hand operations appiied to said skate holder.

9. The structure defined in claim wvhich said template is verticallyadjustable 'clamps for holding two skates with their runners in parallelrelation, said skate holder having a template freely movable in saidguideway and arranged to direct the two skate runners against the twogrinding wheels under the action of gravity and hand operations: appliedto said skate holder and a segmental guide block vertically secured inrespect to the guideway and against which the template is adapted tomove, said s 'iaced tating t that is wl'ieels, a ate holder havingclamps tor hold rtwo skates with their i'll ll l 's in parallo relatioinsa skate holdup; a tou'iplate freely in vable in said ml arranged to diect the two skate ridiners against the two grinning wheels iuider theaction oi gravity and hand operations appl l A led to said s holdeiu and*1 segmental guide block vertically secured L rspect to the guid way andagainst which 1e template is adapted to move, said guide ilocl beingvertically adjustable in respect guideway. said segi inental guide block)eing curved on the arc of a circle of less diameter than the grindingwheel thereby permitting the skate holder to he rocked thereon toincrease the curvature oi the skate runner over that of said template i.a skate grinding machine, thecoinon with a shaft and laterally spacedgrinding wheels carried thereby, of a lateraovable guideway locatedbetween the -'-d grinding wheels and extended horizontally in planeparallel to the planes of said wheels and skate holder having clamps forholding two skates said skate holder being guided by said guideway butbeing freely removable thereirom.

15. The structure defined in claim M. in which said guideway isvertically adjustable and extends in a horizontal plane in the vicinityi the tops of said grinding wheels.

16. The combiintion with a shaft and a, pair of laterally spacedgrinding wheels carried thereby, ot a pair of horizontal parallelplungers extended one at front and the other at the rear of saidgrinding wheels, means for simultaneously moving said plunger-s endwisefirst in one direction and then in the other, a horizontal guidewaylocated between the upper portions of said grinding wheels and carriedby said plungers, and a skate holder having clamps for holding twoskates, said skate holder having template detachably engageable withsaid guidewa to guide the skate runner against said grinding wheels.

17. The structure defined in claim 16 in which said guideway isadjustably supported from said plungers by nut-equipped posts, acooperating pinion-equipped shaft and a worm and worm gear.

in testimony whereof I affix my signature.

VITUS A. BOKER.

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